The present invention generally relates to a storage apparatus and a failure recovery method, and in particular can be suitably applied to a disk array device.
In recent years, as a storage apparatus for storing data in corporations and government offices, a so-called disk array device in which a plurality of hard disk devices are managed and operated in RAID (Redundant Array of Inexpensive Disks) format is being widely used.
With a disk array device, a single RAID group is configured from a prescribed number of hard disk devices, and one or more logical volumes (hereinafter referred to as “logical volumes”) are defined in a storage area provided by the respective hard disk devices configuring one RAID group.
User data from a host apparatus is partitioned into the same size as a block, which is a unit for reading and writing data in the hard disk device, and distributively written into the respective hard disk devices configuring the RAID group together with redundant data (hereinafter referred to as “parity data”) created based on such user data.
As a result of this parity data, even if one or two of the hard disk devices configuring the RAID group are blocked due to a failure, user data stored in the hard disk device which has been blocked (hereinafter referred to as the “blocked hard disk device” as appropriate) can be restored based on the corresponding user data and the corresponding parity data stored in the other hard disk devices.
Japanese Patent Laid-Open Publication No. 2003-167690 and Japanese Patent Laid-Open Publication No. 2002-175158 disclose inventions related to the technology of recovering data stored in a blocked hard disk device using the foregoing parity data.